| Message ID | 1467803094-10473-5-git-send-email-mika.kahola@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 06, 2016 at 02:04:48PM +0300, Mika Kahola wrote: > Helper routine to read out maximum supported bits per > component for DisplayPort legay converters. > > v2: Return early if detailed port cap info is not available. > Replace if-else ladder with switch-case (Ville) Reviewed-by: Jim Bride <jim.bride@linux.intel.com> > > Signed-off-by: Mika Kahola <mika.kahola@intel.com> > --- > drivers/gpu/drm/drm_dp_helper.c | 42 +++++++++++++++++++++++++++++++++++++++++ > include/drm/drm_dp_helper.h | 2 ++ > 2 files changed, 44 insertions(+) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 0d4117c..95d624a 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -471,6 +471,48 @@ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], > } > EXPORT_SYMBOL(drm_dp_downstream_max_clock); > > +/** > + * drm_dp_downstream_max_bpc() - extract branch device max > + * bits per component > + * @dpcd: DisplayPort configuration data > + * @port_cap: port capabilities > + * > + * Returns max bpc on success or 0 if max bpc not defined > + */ > +int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], > + const u8 port_cap[4]) > +{ > + int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; > + bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & > + DP_DETAILED_CAP_INFO_AVAILABLE; > + int bpc; > + > + if (!detailed_cap_info) > + return 0; > + > + switch (type) { > + case DP_DS_PORT_TYPE_VGA: > + case DP_DS_PORT_TYPE_DVI: > + case DP_DS_PORT_TYPE_HDMI: > + case DP_DS_PORT_TYPE_DP_DUALMODE: > + bpc = port_cap[2] & DP_DS_MAX_BPC_MASK; > + > + switch (bpc) { > + case DP_DS_8BPC: > + return 8; > + case DP_DS_10BPC: > + return 10; > + case DP_DS_12BPC: > + return 12; > + case DP_DS_16BPC: > + return 16; > + } > + default: > + return 0; > + } > +} > +EXPORT_SYMBOL(drm_dp_downstream_max_bpc); > + > /* > * I2C-over-AUX implementation > */ > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index de8e9ae..47ae8ed 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -808,6 +808,8 @@ int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link); > int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link); > int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], > const u8 port_cap[4]); > +int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], > + const u8 port_cap[4]); > > void drm_dp_aux_init(struct drm_dp_aux *aux); > int drm_dp_aux_register(struct drm_dp_aux *aux); > -- > 1.9.1
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 0d4117c..95d624a 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -471,6 +471,48 @@ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], } EXPORT_SYMBOL(drm_dp_downstream_max_clock); +/** + * drm_dp_downstream_max_bpc() - extract branch device max + * bits per component + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Returns max bpc on success or 0 if max bpc not defined + */ +int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; + bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & + DP_DETAILED_CAP_INFO_AVAILABLE; + int bpc; + + if (!detailed_cap_info) + return 0; + + switch (type) { + case DP_DS_PORT_TYPE_VGA: + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + case DP_DS_PORT_TYPE_DP_DUALMODE: + bpc = port_cap[2] & DP_DS_MAX_BPC_MASK; + + switch (bpc) { + case DP_DS_8BPC: + return 8; + case DP_DS_10BPC: + return 10; + case DP_DS_12BPC: + return 12; + case DP_DS_16BPC: + return 16; + } + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dp_downstream_max_bpc); + /* * I2C-over-AUX implementation */ diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index de8e9ae..47ae8ed 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -808,6 +808,8 @@ int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link); int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link); int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4]); +int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]); void drm_dp_aux_init(struct drm_dp_aux *aux); int drm_dp_aux_register(struct drm_dp_aux *aux);
Helper routine to read out maximum supported bits per component for DisplayPort legay converters. v2: Return early if detailed port cap info is not available. Replace if-else ladder with switch-case (Ville) Signed-off-by: Mika Kahola <mika.kahola@intel.com> --- drivers/gpu/drm/drm_dp_helper.c | 42 +++++++++++++++++++++++++++++++++++++++++ include/drm/drm_dp_helper.h | 2 ++ 2 files changed, 44 insertions(+)